With the development of the Internet technology, communication requirements extend from traditional low-speed services such as telephone, fax, and telegram to high-speed broadband services such as Internet access, videophone, and video on demand. Users require higher and higher Internet access rates, and the low-speed Internet access mode of the traditional dialup modem can hardly meet user requirements.
Meanwhile, more and more users access a metropolitan area network, and therefore, the users' service requirements are expanding, and the broadband metropolitan area network has a tendency of developing into a multi-service bearer network. A broadband remote access server (Broadband Remote Access Server, hereinafter BRAS) has flexible access authentication, efficient address management function, and powerful user management function, and can provide rich and flexible service and control functions. Therefore, the BRAS can effectively manage and control users who access the broadband metropolitan area network and services used by the users.
An authentication authorization accounting (Authentication Authorization Accounting, hereinafter AAA) server provides the functions of authentication, authorization, and accounting for the users. The AAA server of the user may be implemented through various protocols, and the most commonly used protocol is Remote Authentication Dial In User Service (Remote Authentication Dial In User Service, hereinafter RADIUS). The RADIUS protocol is an application layer communication protocol between the BRAS and the AAA server, and an AAA server based on the RADIUS protocol is called a RADIUS server.
When there are many BRAS access users, multiple RADIUS servers are generally deployed in the network to share the load. On one side, each RADIUS server can perform authentication, authorization and accounting for any user, and on the other hand, each RADIUS server can perform access authentication for users of multiple BRASs.
In the prior art, the RADIUS load sharing of the BRAS is primarily controlled by configuring command lines. For example, if 2 RADIUS servers are available in the network, a 1:1 ratio may be configured on the BRAS to share the load of functions such as authentication, authorization and accounting for the user.
However, when there are many access users, a RADIUS server may be too busy to respond to the user's authentication requests in time, and the BRAS works at the fixed load sharing ration only, and cannot make adjustment according to the current respective state of the RADIUS server. Consequently, some users fail to access the network due to authentication timeout.